The design and incorporation of an auger-based extrusion system into a desktop printer for use in 3D printing of a thermosetting epoxy polymer is presented. The extrusion head design allows for liquid deposition of a dynamic covalent polymer, which demonstrates reversible dissociation to a liquid at elevated temperatures followed by solidification and fast curing upon cooling to room temperature. Studies on material printability were performed by varying printing parameters (extrusion rate, printing speed, barrel temperature and bed temperature). Printing parameters were optimized to yield printed parts with minimal deviation from the digital part model dimensions. The fast reactivity of the material resulted in improved interlayer adhesion, leading to mechanical performance comparable to traditional cast-molded parts. Parameters were also tuned for the printing of nanoparticle composites. Multimaterial parts, which demonstrated varying and mismatched material properties, were successfully additively manufactured. This work provides insight into the additive manufacturing of covalently crosslinked polymers and their respective nanocomposites. The results show a promising avenue to the additive manufacturing of mechanically graded and mismatched multimaterial parts.
- Describe a new method to printing thermosetting polymers.
- Describe an approach to liquid deposition modeling.
- Identify significant challenges in polymer additive manufacturing.